Forums: Climbing Information: The Lab:
Triple Figure-Eight Loop
RSS FeedRSS Feeds for The Lab

Premier Sponsor:

 


shu2kill


Aug 14, 2008, 7:13 AM
Post #1 of 14 (6302 views)
Shortcut

Registered: Apr 8, 2008
Posts: 349

Triple Figure-Eight Loop
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

hey, do any of you know the strenght rating for the Triple Figure-Eight Loop ???

http://www.layhands.com/Knots/Knots_TripleLoops.htm

i would like to know how much does it decreases the rope strenght.

thanx!!


(This post was edited by shu2kill on Aug 14, 2008, 7:17 AM)


Partner j_ung


Aug 14, 2008, 7:14 AM
Post #2 of 14 (6301 views)
Shortcut

Registered: Nov 21, 2003
Posts: 18687

Re: [shu2kill] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

shu2kill wrote:
hey, do any of you know the strenght rating for the Triple Figure-Eight Loop ???

http://www.layhands.com/...nots_TripleLoops.htm

i would like to know how much does it decreases the rope strenght.

thanx!!

Clicky! Smile


shu2kill


Aug 14, 2008, 7:18 AM
Post #3 of 14 (6292 views)
Shortcut

Registered: Apr 8, 2008
Posts: 349

Re: [j_ung] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

j_ung wrote:
shu2kill wrote:
hey, do any of you know the strenght rating for the Triple Figure-Eight Loop ???

http://www.layhands.com/...nots_TripleLoops.htm

i would like to know how much does it decreases the rope strenght.

thanx!!

Clicky! Smile

thanx!!


ja1484


Aug 14, 2008, 7:54 AM
Post #4 of 14 (6262 views)
Shortcut

Registered: Aug 10, 2006
Posts: 1935

Re: [shu2kill] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

shu2kill wrote:
Hey, do any of you know the strength rating for the Triple Figure-Eight Loop?


Strong enough.


GeneralZon


Aug 14, 2008, 8:46 AM
Post #5 of 14 (6214 views)
Shortcut

Registered: May 9, 2008
Posts: 273

Re: [ja1484] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

What are you planning on using the triple 8 for? Just curious.


acorneau


Aug 14, 2008, 11:28 AM
Post #6 of 14 (6142 views)
Shortcut

Registered: Feb 6, 2008
Posts: 2889

Re: [shu2kill] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

shu2kill wrote:
hey, do any of you know the strenght rating for the Triple Figure-Eight Loop ???...
i would like to know how much does it decreases the rope strenght.

My guess is that it should be about the same (if not slightly better than) than a standard figure-8; maintaining 75-80% of single-strand strength.


shu2kill


Aug 14, 2008, 11:31 AM
Post #7 of 14 (6139 views)
Shortcut

Registered: Apr 8, 2008
Posts: 349

Re: [acorneau] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

thanx.

a friend asked me to investigate the numbers. he said something about building anchors, but he wanted to know the strenght, to determine if its better than the knots he currently use or something.

thanx!!


irregularpanda


Aug 14, 2008, 12:13 PM
Post #8 of 14 (6113 views)
Shortcut

Registered: Mar 13, 2007
Posts: 1364

Re: [shu2kill] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

shu2kill wrote:
thanx.

a friend asked me to investigate the numbers. he said something about building anchors, but he wanted to know the strenght, to determine if its better than the knots he currently use or something.

thanx!!

If you want the real numbers, adatesman would probably know for sure. You can rest assured that it is strong as hell(or at least as strong as the pieces used and how they are connected), and inherently redundant.


jon5rockjock


Aug 16, 2008, 7:18 AM
Post #9 of 14 (5959 views)
Shortcut

Registered: Jul 4, 2008
Posts: 1

Re: [irregularpanda] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

I just recently checked out the triple loop figure 8. and it is interesting. I immediately thought about an anchoring application. However,....i suppose that if any particular piece in the system popped you would see a shockloading of sorts occur. there also seems to be a lack a top shelf although there are methods around that by adding an Alp Butt and then a preferred knot further below it to anchor into for the belayer. I personally prefer the the standard nylon cordelette and very rarely stray from this method. There are 100 ways to skin a cat though and I tend to do what seems tried and true for me.

I am curious on the technical data/testing of the double figure 8 or "Super 8". Please refer any links if you know or come across them.


knudenoggin


Aug 16, 2008, 8:38 PM
Post #10 of 14 (5902 views)
Shortcut

Registered: May 6, 2004
Posts: 594

Re: [shu2kill] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

shu2kill wrote:
a friend asked me to investigate the numbers. he said something about building anchors, but he wanted to know the strength, to determine if its better than the knots he currently use or something.

This is a misguided query: the "numbers" won't be any indication of whether
to use the knot in comparison with some other knot's numbers. For starters,
you have really no valid reason--probably--to conclude that the "numbers"
you might see apply to the particular physical knot you will tie, or for the
particular material you use. Here we're concerned with a triple-eye knot:
how do you think it would be tested, to generate some "numbers"?
--once for each eye in isolation? --and after others bore some load,
or without that? --or two of three eyes ... ? ... and on & on.
(If you dress & set the knot as shown on the Layhands site, expect it
to be weaker than it would be in some other dressings--he'd put a pretty
hard bend at the mainlines' entry.)

Of concern with a multi-eye knot is inter-eye feeding of material if an eye
is unloaded (anchor point failure). This one should be pretty secure.

*kN*


shu2kill


Aug 16, 2008, 10:16 PM
Post #11 of 14 (5875 views)
Shortcut

Registered: Apr 8, 2008
Posts: 349

Re: [knudenoggin] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

well, i agree the numbers wont be 100% accurate for the particular knot i can do, but i think they would be close.

i asked him what he needed the knot for, and told him your replies, and he said that, for an anchor, he puts each loop of a double figure 8 on a biner. but the sharp bend also reduces the strenght. so, he wanted to see what would be stronger, a rope with a triple figure 8, or one with a double. the reasoning was that the triple could divide the load in 3 parts. but maybe the loss of strenght due to the knot itself, was bigger than the loss of strenght due to a double 8 with each loop in a biner.

thanx!


summerprophet


Aug 16, 2008, 10:23 PM
Post #12 of 14 (5872 views)
Shortcut

Registered: Jan 16, 2004
Posts: 764

Re: [shu2kill] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

Tell your friend that the knot on its own is going to be stronger than the knot you use to tie in with.

In short, certainly strong enough.

I am assuming he is using his lead rope to create the anchor, if he isn't there are far easier and faster methods I would look into.


knudenoggin


Aug 17, 2008, 7:01 PM
Post #13 of 14 (5786 views)
Shortcut

Registered: May 6, 2004
Posts: 594

Re: [shu2kill] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

shu2kill wrote:
... the reasoning was that the triple could divide the load in 3 parts. but maybe the loss of strength due to the knot itself, was bigger than the loss of strength due to a double 8 with each loop in a biner.

Consider this: a Fig.8 loopknot in 11m rope pulled with a 'biner in the eye
breaks at the knot. ONEye, noTwo, noThree--one.

*kN*


gunkiemike


Aug 22, 2008, 7:10 PM
Post #14 of 14 (5029 views)
Shortcut

Registered: Oct 1, 2002
Posts: 2263

Re: [shu2kill] Triple Figure-Eight Loop [In reply to]
Report this Post
Average: avg_1 avg_2 avg_3 avg_4 avg_5 (0 ratings)  
Can't Post

Get your friend off this notion of "accuracy" in testing for these types of knots. Consider this - the angle between eyes will affect the load seen by the knot and therefore tensile strength. So in a perfect world you'd have a matrix of angles and failure loads. Absolutely useless for making field decisions. Bottom line - a Fig 8 loop type knot in the climbing rope is strong enough. Now turn off the computer and go to bed. Cool


Forums : Climbing Information : The Lab

 


Search for (options)

Log In:

Username:
Password: Remember me:

Go Register
Go Lost Password?



Follow us on Twiter Become a Fan on Facebook